1. Field of the Invention
The present invention relates to a polymer compound having excellent heat resistance and excellent insulating property, a positive highly heat-resistant photosensitive resin composition used for a surface protecting film and/or an interlayer insulating film of a semiconductor device, or for a planarization film and/or an interlayer insulating film of a display device, a method for forming a cured relief pattern having heat resistance using the positive highly heat-resistant photosensitive resin composition, and an electronic device for a semiconductor device, and for a display device, having a relief pattern.
2. Description of the Related Art
In a surface protecting film and/or the interlayer insulating film of a semiconductor device, a polyimide resin having each of excellent heat resistance, electric property and mechanical property is used. The polyimide resin is currently generally supplied in the form of a photosensitive polyimide precursor composition. The photosensitive polyimide precursor composition may be easily formed into a surface protecting film or an interlayer insulating film of a semiconductor device, or a planarization film or an interlayer insulating film of a display device, by applying the composition onto a substrate, and performing patterning with active light rays, development, and thermal imidation, whereby processing may be considerably shortened as compared with a case using a conventional non-photosensitive polyimide precursor composition.
However, when a photosensitive polyimide precursor composition is used, it is necessary to use a large amount of an organic solvent such as N-methyl-2-pyrrolidone as a developer in the developing step. For this reason, due to growing concerns about environmental problems in recent years, strategies to avoid use of an organic solvent agent have been sought.
As a result, recently, various proposals have been made for a heat-resistant photosensitive resin material including a photosensitive polyimide precursor and/or a photosensitive polybenzoxazole precursor, which can be developed with an aqueous alkali solution in a similar manner to a photoresist (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2004-133088). However, in a heat resistant resin material in which naphthoquinonediazide is added to a photosensitive polyimide precursor or photosensitive polybenzoxazole precursor, the effect of inhibiting dissolution of naphthoquinonediazide in an aqueous alkali solution is insufficient, and pattern forming property is insufficient.
In addition, another positive photosensitive resin including a polyphenylene oxide resin that is obtained by oxidative coupling polymerization using a copper catalyst has been proposed (see, for example, JP-A No. 2000-275842). However, it has been found that the polyphenylene oxide resin has insufficient heat resistance and insufficient insulating property. Although the cause has not been clarified, as one hypothesis it is presumed that since the resin is synthesized by oxidative coupling polymerization with a copper catalyst, there is a possibility that the catalyst remains in the resin, and that the deficiencies result from this.